Dan Kail was vacationing in Las Vegas when he heard that the temperature at Death Valley could approach 130F (54C) this weekend. He didn't hesitate to make a trip to the desert location that is typically the hottest place on the planet.

"Coming to Death Valley in the summertime has always been on the top of my bucket list," the 67-year-old Pittsburgh man said. "When I found out it might set a record I rented a car and drove straight over. If it goes above 130F I will have something to brag about."

The forecast called for Death Valley to reach 128F Saturday as part of a heat wave that has caused large parts of the western US to suffer. Death Valley's record high of 134F, set a century ago, stands as the highest temperature ever recorded on earth.

"The wind out here is like being in front of a blast furnace," Kail said.

As temperatures soared in Las Vegas on Friday, 200 people were treated for heat problems at an outdoor concert, Clark County spokesman Erik Pappa said.

Thirty of them were hospitalized for heat-related injuries at Vans Warped Tour at Silverton Casino as temps reached 115F.

Most of the others "were essentially provided shade and water and a place to sit down," Pappa said.

It was expected to get even hotter in Las Vegas over the weekend.

Phoenix reached 116F on Friday — 2F short of the expected high — in part because a light layer of smoke from wildfires in neighboring New Mexico shielded the blazing sun, the National Weather Service said. Phoenix was forecast to hit nearly 120. The record in Phoenix is 122.

The heat was so punishing that rangers took up positions at trailheads at Lake Mead in Nevada to persuade people not to hike. Zookeepers in Phoenix hosed down the elephants and fed tigers frozen fish snacks. Dogs were at risk of burning their paws on scorched pavement, and airlines kept close watch on the heat for fear that it could cause flights to be delayed.

The heat wasn't expected to break until Monday or Tuesday.

The scorching weather presented problems for airlines because high temperatures can make it more difficult for planes to take off. Hot air reduces lift and also can diminish engine performance. Planes taking off in the heat may need longer runways or may have to shed weight by carrying less fuel or cargo.

Smaller jets and propeller planes are more likely to be affected than bigger airliners that are better equipped for extreme temperatures.

Temperatures are also expected to soar across Utah and into Wyoming and Idaho, with triple-digit heat forecast for the Boise area. Cities in Washington state that are better known for cool, rainy weather should break the 90s next week.

"This is the hottest time of the year, but the temperatures that we'll be looking at for Friday through Sunday, they'll be toward the top," said weather service meteorologist Mark O'Malley. "It's going to be baking hot across much of the entire west."

The heat is the result of a high-pressure system brought on by a shift in the jet stream, the high-altitude air current that dictates weather patterns. The jet stream has been more erratic in the past few years.

Health officials warned people to be extremely careful when venturing outdoors. The risks include not only dehydration and heat stroke but burns from the concrete and asphalt. Dogs can suffer burns and blisters on their paws by walking on hot pavement.

"You will see people who go out walking with their dog at noon or in the middle of the day and don't bring enough water and it gets tragic pretty quickly," said Bretta Nelson, spokeswoman for the Arizona Humane Society. "You just don't want to find out the hard way."

Cooling stations were set up to shelter the homeless and elderly people who can't afford to run their air conditioners. In Phoenix, Joe Arpaio, the famously hard-nosed sheriff who runs a tent jail, planned to distribute ice cream and cold towels to inmates this weekend.

Officials said personnel were added to the Border Patrol's search-and-rescue unit because of the danger to people trying to slip across the Mexican border. At least seven people have been found dead in the last week in Arizona after falling victim to the brutal desert heat.

In June 1990, when Phoenix hit 122F, airlines were forced to cease flights for several hours because of a lack of data from the manufacturers on how the aircraft would operate in such extreme heat.

US Airways spokesman Todd Lehmacher said the airline now knows that its Boeings can fly at up to 126, and its Airbus fleet can operate at up to 127.

While the heat in Las Vegas is expected to peak Sunday, it's unlikely to sideline the first round of the four-week Bikini Invitational tournament.

"I feel sorry for those poor girls having to strut themselves in 115F, but there's $100,000 up for grabs," said Hard Rock casino spokeswoman Abigail Miller. "I think the girls are willing to make the sacrifice."